This invention relates to an offshore lift platform, comprising a platform proper with a plurality of support legs arranged shiftable, each leg being retained through the intermediary of latch hole rows arranged in horizontal and vertical spacings and advance means climbing in increments in that at the platform in the spacing of the latch hole rows latches are arranged above one another and the lower latches are stationarily positioned at the platform, whereas the upper latches are arranged height-adjustable relative to the platform via a positioner and are interconnected via a ring.
Mobile offshore structures of this type correspond to the so-called "jack up" principle, the platform being built as buoyant body and the legs or columns being held in the or at the platform via latches and being movable in vertical direction via advance means. For doing so, the latches in the upper row are withdrawn from the sockets of the legs and shifted by means of hydraulic cylinders into the next higher or lower latch hole row. Subsequently, the lower row of latches is withdrawn from the sockets, and by means of the hydraulic cylinders a corresponding movement of the platform is effected, and the latches are reengaged with the leg.
Such apparatus are already known from German Auslegeschrift No. 2,549,746. It has been noted, however, that for large dimensions of the legs it is extremely difficult and very costly in manufacturing aspects to in particular tolerate the vertical spacings of the latch hole rows so closely as would be required in order to achieve a uniform loading of the individual latches.